KR20100066752A - Color filter substrate for in-plain switching mode liquid crystal display device and method of fabricating the same - Google Patents

Abstract

PURPOSE: A color filter substrate for in-plain switching mode liquid crystal display device is provided to reduce manufacturing costs by forming a back plate of a color filter substrate with indium-tin-oxide of 1/20. CONSTITUTION: The back plate of the first thickness is formed in the rear side of the insulating substrate(110). The back plate(113) of the first thickness is formed with a transparent conductive compound. The black matrix(115) is formed on the back plate while having a plurality of openings upon the top side of the substrate. The color filter layer(120) is formed with a plurality of openings surrounded by the black matrix. The overcoat layer(125) is formed over the color filter layer and black matrix.

Description

Color filter substrate for in-plain switching mode liquid crystal display device and method of fabricating the same}

The present invention relates to a liquid crystal display device, and more particularly, to a color filter substrate for a transverse electric field type liquid crystal display device and a method of manufacturing the same that can reduce the manufacturing cost.

Recently, with the rapid development of the information society, the necessity of flat panel displays having excellent characteristics such as thinning, light weight, and low power consumption has emerged. Among them, liquid crystal displays have a resolution, It is excellent in color display and image quality, and is actively applied to notebooks and desktop monitors.

In general, a liquid crystal display device arranges two substrates having electrodes formed on one surface thereof so that the surfaces on which the electrodes are formed face each other, interposes a liquid crystal material between the two substrates, and then applies a voltage to the electrodes formed on the substrates. The liquid crystal molecules are moved by an electric field generated by application, thereby representing an image by the transmittance of light that varies accordingly.

1 is a view schematically showing a general liquid crystal display device.

As shown, the general liquid crystal display device 1 includes a color filter layer 26 including red, green, and blue color filter patterns 26a, 26b, and 26c on the inner surface of the transparent insulating substrate 22, and the respective colors. An upper substrate 10 provided with a black matrix 25 formed between the filter patterns 26a, 26b, and 26c, a common electrode 28 deposited covering the color filter layer 26 and the black matrix 25; Gates and data lines 14 and 16 formed on the transparent insulating substrate 12 to define the pixel regions P, and the pixel electrodes 18 and the switching elements formed on the pixel regions P, respectively. The lower substrate 10 includes Tr, and the liquid crystal 30 is filled between the upper substrate 20 and the lower substrate 10.

The lower substrate 10 may also be referred to as an array substrate, and a plurality of gate lines 14 may be formed at equal intervals and extend in one direction, and may have a plurality of gate lines 14 having equal intervals. The data line 16 is formed, and the thin film transistor Tr, which is a switching element, is formed at the intersection of the two lines 14 and 16. In this case, the gate line 14 and the data line 16 cross each other to define a plurality of pixel regions P, and a transparent pixel electrode 18 is formed on the pixel region P.

Meanwhile, a black matrix 25 is formed on the upper substrate 20, which is a color filter substrate, to block light leakage in a matrix form corresponding to each of the wirings 14 and 16 of the lower substrate 10 described above. The color filter layer 26 including red, green, and blue color filter patterns 26a, 26b, and 26c, which are sequentially repeated, is formed in the opening surrounded by the black matrix 25, and below the color filter layer 26. The common electrode 28 is formed on the entire surface as a transparent conductive material.

The liquid crystal display device 1 having the structure as described above includes a color filter substrate 20 on which the common electrode 28 is formed, an array substrate 10 on which the pixel electrode 18 is formed, and the two substrates 20 and 10. It consists of a liquid crystal 30 interposed therebetween, in the liquid crystal display device 1 in such a way that the liquid crystal is driven by an electric field applied up and down between the common electrode 28 and the pixel electrode 18, such as transmittance and aperture ratio, etc. Excellent property

However, the liquid crystal drive due to the electric field applied up and down has a disadvantage that the viewing angle characteristics are not excellent.

Accordingly, a transverse field type liquid crystal display device having excellent viewing angle characteristics has been proposed to overcome the above disadvantages.

2 is a view schematically showing a cross section of a general transverse electric field type liquid crystal display device.

As shown in the figure, the transverse electric field type liquid crystal display device 40 has an upper substrate 60, which is a color filter substrate, and a lower substrate 50, which is an array substrate, facing each other, facing each other, and the upper and lower substrates 60, 50, respectively. The liquid crystal layer 70 is interposed in between. The common electrode 55 and the pixel electrode 58 are formed on the lower substrate 50 on the same plane. In this case, the liquid crystal layer 70 is formed by the common electrode 55 and the pixel electrode 58. It is operated by the horizontal electric field (L).

In the transverse electric field type liquid crystal display device 40 having the above-described configuration, there is no phase change of the liquid crystal at a position corresponding to the common electrode 55 and the pixel electrode 58 when a voltage is applied, but the common electrode 55 and the pixel electrode The liquid crystals located in the interval between 58 are arranged in the same direction as the horizontal electric field L by the horizontal electric field L formed by applying a voltage between the common electrode 55 and the pixel electrode 58. . That is, since the liquid crystal moves by the horizontal electric field L of the horizontal field type liquid crystal display device 40, the viewing angle is widened. Thus, as seen the lateral jeongyehyeong liquid crystal display device 40 from the front, the up / down / left / right direction in the direction of about 80~85 ^o it can be visible without reversal.

Meanwhile, the transverse electric field type liquid crystal display device 40 having the above-described configuration manufactures the array substrate 50 and the color filter substrate 60, respectively, and seals the two substrates 50 and 60 along the edge thereof. It can be completed by forming (not shown), inject | pouring a liquid crystal, and bonding together.

At this time, a lot of static electricity is generated in the process of the unit process is mounted on the stage (not shown) of the unit processing equipment for the process progress in each step in the manufacturing of each substrate (50, 60).

Since the wiring and the electrodes 55 and 58 made of a metal material are formed on the array substrate 50, the static electricity can be effectively removed through the array substrate 50. However, the transverse electric field liquid crystal in which the common electrode 55 is formed on the array substrate 50 is formed. In the case of the color filter substrate 60 for a display device, since there is no component made of a conductive material, the color filter substrate 60 is very vulnerable to static electricity generated during unit process or movement. In addition, even though the color filter substrate 60 is manufactured as a complete product, the color filter substrate 60 does not have a component made of a conductive material, and thus there is no means for removing the charge charged by static electricity.

Therefore, indium tin oxide (ITO) or indium- which is a transparent conductive material on the back surface of the color filter substrate 60 to discharge the static electricity generated during the progress of the unit process and effectively discharge the charged charge during the formation of the finished product Zinc-oxide (IZO) is deposited through sputtering to form a back electrode (not shown), and then a unit process for forming a color filter layer is performed.

However, indium tin oxide (ITO) or indium zinc oxide (IZO), which is a transparent conductive material used to form a back electrode (not shown) of the color filter substrate 60, is a very expensive conductive metal material and thus, manufacturing cost Has become a factor to improve. Indium, the main raw material of indium tin oxide (ITO) or indium zinc oxide (IZO), is a rare metal, and its price is rising rapidly. There is a situation.

In addition, in manufacturing the color filter substrate 60, a defect occurs in reworking, and the indium tin oxide (ITO) or indium zinc oxide (not shown) constituting the back electrode (not shown) IZO) has a relatively strong characteristic in the color filter layer, the chemical solution for removing the black matrix is not removed when removing it, the situation is affected by the chemical solution for the removal of the overcoat layer. In this case, if a defect occurs in the color filter layer forming step, the back electrode is not affected by the chemicals for removing the color filter layer and the black matrix, and thus only the black matrix and the color filter layer are removed by reworking and removing the color filter. Although a process for manufacturing a substrate may be performed, when a defect occurs during the formation of an overcoat layer, partial etching occurs due to the chemical liquid for removal thereof. Therefore, in this case, a separate rework process must be performed to completely remove the back electrode.

Therefore, when the back electrode is formed of indium tin oxide (ITO) or indium zinc oxide (IZO), a separate rework process line is required for this purpose. There is a need for a problem that increases the manufacturing cost again.

The present invention has been made to solve the conventional problems, color filter substrate for a transverse electric field type liquid crystal display device and a method of manufacturing the same, which can facilitate the suppression and removal of static electricity generation, can be manufactured at a low cost and free supply To provide that purpose.

When defects occur during the formation of color filters or overcoat layers, unified rework is possible to reduce the initial investment cost compared to the conventional dual rework process, thereby reducing manufacturing costs and reducing rework time. Another object of the present invention is to improve productivity of color filters for electric field type liquid crystal display devices.

Color filter substrate for a transverse electric field type liquid crystal display device according to an embodiment of the present invention for achieving the above object is formed on the back surface of the insulating substrate, the compound containing zinc oxide (ZnO) and divalent to tetravalent elements A back electrode having a first thickness made of a transparent conductive material; A grating black matrix having a plurality of openings on an upper surface of the substrate on which the rear electrode is formed; A color filter layer formed in a plurality of openings surrounded by the black matrix; And an overcoat layer formed on a front surface of the color filter layer and the black matrix.

The first thickness is characterized in that 200 ~ 300 kHz.

A color filter substrate for a transverse electric field type liquid crystal display device according to another embodiment of the present invention is formed on the back surface of an insulating substrate, and includes a transparent conductive material including a compound containing zinc oxide (ZnO) and a divalent to tetravalent element. It consists of a first layer of a first thickness consisting of a second layer of a second thickness consisting of indium tin oxide (IZO) or indium zinc oxide (IZO) of the first layer and the second layer A rear electrode having a double layer structure stacked in order or stacked in a second layer and a first layer; A black matrix having a lattice shape having a plurality of openings on an upper surface of the substrate on which the back electrode of the double layer structure is formed; A color filter layer formed in a plurality of openings surrounded by the black matrix; And an overcoat layer formed on a front surface of the color filter layer and the black matrix.

In this case, the first thickness is 100 kPa to 250 kPa, the second thickness is 50 kPa to 100 kPa, and the sum of the first and second thickness is 200 kPa to 300 kPa.

The compound containing the divalent to tetravalent element is characterized in that Al ₂ O ₃ , Ga ₂ O ₃ , CaO, wherein the transparent conductive material, zinc oxide (ZnO) 94.95 to 98.79% by weight, Al ₂ O ₃ 1 to 3 wt%, Ga ₂ O ₃ 0.2 to 2% by weight, and CaO 0.01 to 0.05 or comprises a% by weight, or zinc oxide (ZnO) 95% to 98.8% by weight, Al ₂ O ₃ 1% by weight To 3% by weight, Ga ₂ O ₃ It is characterized by consisting of 0.2% to 2% by weight.

In a method of manufacturing a color filter substrate for a transverse electric field type liquid crystal display device according to an embodiment of the present invention, a transparent conductive material including a compound containing zinc oxide (ZnO) and a divalent to tetravalent element on a back surface of an insulating substrate is provided. Depositing to form a first back electrode of a first thickness; Forming a lattice-like black matrix having a plurality of openings on an upper surface of the substrate on which the rear electrode is formed; Forming a color filter layer in the plurality of openings surrounded by the black matrix; Forming an overcoat layer over the color filter layer and the black matrix.

The first thickness is characterized in that 200 ~ 300 kHz.

An indium tin oxide (IZO) or an indium zinc oxide (IZO) to cover the first back electrode before the first back electrode or after the first back electrode is formed. Forming a second back electrode to have a second thickness.

In this case, the first thickness is 100 kPa to 250 kPa, the second thickness is 50 kPa to 100 kPa, and the sum of the first and second thickness is 200 kPa to 300 kPa.

According to the present invention, the back electrode of the color filter substrate is formed by using zinc oxide (ZnO) whose unit price is 1/20 of indium tin oxide (ITO), thereby reducing the material cost and finally reducing the manufacturing cost. have.

In addition, when depositing on a substrate through sputtering using zinc oxide (ZnO) as a target material, pure oxygen (O 2) is not required, thereby further reducing material costs.

In addition, the present invention has a higher transmittance than the back electrode made of indium tin oxide (ITO) of the same thickness, thereby improving the luminance characteristics.

In addition, the second embodiment of forming a back electrode having a double layer structure has an advantage of improving the use efficiency of the sputtering device.

In addition, when the color filter substrate is defective, the same stripping liquid is used to remove the back electrode and the color filter layer, thereby eliminating the need for a separate rework process for removing the back electrode, thereby simplifying the rework process and preventing initial equipment investment. There is an advantage.

Hereinafter, a color filter substrate for a transverse electric field type liquid crystal display device and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings.

<First Embodiment>

3A to 3F are cross-sectional views illustrating manufacturing steps of a color filter substrate for a transverse electric field type liquid crystal display device according to a first exemplary embodiment of the present invention.

First, as shown in FIG. 3A, the transparent insulating substrate 110 is positioned in a chamber (not shown) of the sputtering apparatus, and then a series magnetron sputtering is performed to form a back electrode 113 having a thickness of about 200 kPa to about 300 kPa. . In this case, the back electrode 113 is a transparent conductive material mainly containing zinc oxide (ZnO), which is very inexpensive, and added two or three small amounts of a compound having a divalent to tetravalent valence. In this case, the compound having a valence of divalent to tetravalent is Al ₂ O ₃ , Ga ₂ O ₃ , CaO, Al ₂ O ₃ is 1% to 3% by weight, Ga ₂ O ₃ is 0.2% to 2% by weight %, And CaO is characterized in that it is mixed with the zinc oxide (ZnO) in a ratio of 0.01% to 0.05% by weight, in this case CaO may not be added.

Therefore, when the transparent conductive material according to the first embodiment of the present invention includes all three compounds, zinc oxide (ZnO) 94.95% by weight to 98.79% by weight, Al ₂ O ₃ 1% by weight to 3%, 0.2% to 2% by weight of Ga ₂ O ₃ , and 0.01% to 0.05% by weight of CaO, and, if including two compounds, 95% to 98.8% by weight of zinc oxide (ZnO), Al ₂ O ₃ It is characterized by consisting of 1% by weight to 3% by weight, Ga ₂ O ₃ 0.2% by weight to 2% by weight.

On the other hand, as described above, the reason for including the compound containing a divalent to tetravalent in the transparent conductive material is to improve the target properties and conductivity for sputtering.

For example, a transparent conductive material having a content ratio of 96.99% by weight of zinc oxide (ZnO), ₂ % by weight of Al ₂ O ₃ , 1% by weight of Ga ₂ O ₃ , and 0.01% by weight of CaO, and has a thickness of about 200 μs. In the case of forming the electrode 113, the average transmittance of light having a wavelength range of 400 nm to 700 nm was 97.8%, and the specific resistance value was found to be 246.8 × 10 ⁻⁴ μm ⁻¹ , and the same content ratio as described above When the back electrode 113 was formed with the thickness of about 300 GPa, it was found that the average transmittance was 96.7% and the specific resistance was 34.6 × 10 ^-4 Ωcm ^-1 .

On the other hand, in the case of forming the back electrode 113 having a thickness of 200 듐 as indium tin oxide (ITO) as a comparative example, the average transmittance for light having a wavelength range of 400nm to 700nm is 96.8%, the specific resistance value is 3.7 It turned out that it is * 10 <^-4> cm <^-1> .

Therefore, when the back electrode 113 made of zinc oxide (ZnO) and the back electrode 113 made of conventional indium tin oxide (ITO) have the same thickness, according to an embodiment of the present invention. Comparing the characteristics, it can be seen that the first embodiment of the present invention is superior in terms of transmittance of about 1.1%, and in terms of conductivity, the specific resistance value is made of ITO, which is a low value. It was found that what was done was a little better.

However, it can be seen experimentally that the back electrode 113 for suppressing static electricity can play a role of removing static electricity without any difficulty when its resistivity is lower than 500 × 10 ⁻⁴ μm ⁻¹ .

Therefore, the back electrode 113 made of a transparent conductive material whose main component is zinc oxide (ZnO) according to the first embodiment of the present invention has a conductivity lower than that of a conventional indium-tin-oxide (ITO) material, but eliminates static electricity. It does not have any problem in performing the role of, and it is superior to indium tin oxide (ITO) in terms of transmittance, and compared to the conventional indium tin oxide (ITO) in terms of the material cost and supply status of the target to form this It was found to have a much more favorable side.

For reference, the international market trades at about US $ 500,000 per tonne of indium (In) and about US $ 2500 per tonne of zinc (Zn), thereby reducing the raw material cost of indium-tin-oxide (ITO) to zinc oxide. It is about 20 times more expensive than (ZnO). Accordingly, when zinc oxide (ZnO) is used as the back electrode 113 of the color filter substrate, material cost reduction of about 30% is achieved based on the completed transverse field type liquid crystal display device.

On the other hand, when the back electrode 113 having a thickness of about 200 to 300 mW is deposited by sputtering with a transparent conductive material mainly composed of zinc oxide (ZnO), the chamber of the sputtering device is formed with argon (P) to form plasma. Ar) Since only gas is required, the material cost can be further reduced.

The deposition of indium tin oxide (ITO) on a substrate requires a large amount of oxygen (O ₂ ) separately. That is, the argon (Ar) gas for plasma formation must be supplied to the chamber of the sputtering device for indium tin oxide (ITO) deposition, and pure oxygen (O ₂ ) must be supplied separately.

Therefore, when comparing only the sputtering process, forming the back electrode 113 mainly composed of zinc oxide (ZnO) does not require a separate oxygen (O ₂ ) supply. It is possible to reduce the material cost compared to depositing ITO) with the back electrode.

 Next, as shown in FIG. 3B, in the substrate 110 on which the back electrode 113 having a thickness of about 200 to 300 mW is formed of a transparent conductive material mainly composed of zinc oxide (ZnO), the back electrode ( 115 is coated with an epoxy resin having black resin or black series photosensitive characteristics on the entire surface to form a photosensitive black organic insulating layer (not shown).

Subsequently, an exposure mask (not shown) having a transmission region and a blocking region is positioned at a predetermined interval to correspond to the photosensitive black organic insulating layer (not shown), and then exposure is performed through the exposure mask (not shown). The photosensitive black organic insulating layer (not shown) is developed to form a black matrix 115 having a lattice form having a plurality of openings op1, op2, and op3.

Next, as shown in FIG. 3C, a red resist layer 117 is formed by applying a red resist to the entire surface of the substrate 110 on which the black matrix 115 is formed, and a blocking region (above the red resist layer 117). After exposing the exposure mask 190 having a constant pattern of BA) and the transmission area TA, an exposure process is performed.

In this case, since the negative type is mainly used for the color resist including the red resist, the embodiment of the present invention shows that the negative type red (color) resist is used. Accordingly, the exposure mask 190 is positioned and exposed so that the transmission area TA corresponds to the portion where the red color filter pattern 120a of FIG. 3D is to be formed.

Next, as illustrated in FIG. 3D, the exposed red color resist layer (117 of FIG. 3C) is developed, so that the black matrix 115 and the plurality of first openings op1 in the black matrix 115 are formed. A part of the overlapping red color filter pattern 120a is formed. In this case, the red color filter pattern 120a is formed on the entire surface of the substrate 110 at regular intervals.

Next, as shown in FIG. 3E, the green and blue resists are processed in the same manner as the method of forming the red color filter pattern 120a, that is, the green or blue resist coating and the exposure and development process using the exposure mask are performed. In operation, the green and blue color filter patterns 120b and 120c are formed in the second and third openings op2 and op3 surrounded by the black matrix 115 of the lattice shape.

Accordingly, the red, green, and blue color filter patterns 120a, 120b, and 120c are sequentially formed in the first, second, and third openings op1, op2, and op3 between the black matrix 115 in the lattice form, respectively. The color filter layer 120 (120a, 120b, 120c) partially overlapping the black matrix 115 surrounding the first, second, and third openings op1, op2, and op3 is formed.

Next, as shown in FIG. 3F, a colorless transparent organic insulating material example is formed on the color filter layer 120 having the red, green, and blue color filter patterns 120a, 120b, and 120c and the exposed black matrix 115. For example, the photoacryl is coated on the entire surface to form the overcoat layer 125, thereby completing the color filter substrate 150 for the transverse electric field type liquid crystal display device according to the first embodiment of the present invention. In this case, the overcoat layer 125 is formed to protect the color filter layer 120 and to planarize the surface.

Next, although not shown in the drawings, a spacer material layer (not shown) may be formed by selectively coating the entire surface of the photosensitive organic insulating material to form a patterned spacer (not shown) over the overcoat layer 125. By performing exposure and development using a mask (not shown), a patterned spacer (not shown) spaced at a predetermined interval and having a columnar shape may be formed corresponding to a portion where the black matrix 115 is formed. The patterned spacers (not shown) need not be formed and may be omitted when using a ball spacer.

On the other hand, referring to Figure 3f, if a defect occurs during the unit process by the manufacturing process as described above, it is not immediately discarded, but by reworking (rework) to reuse the transparent insulating substrate 110 have. That is, if a defect occurs when the black matrix 115, the color filter layer 120, or the overcoat layer 125 is formed, it is moved to a process line for reworking, and the defect is caused by a rework process. The generated overcoat layer 125, the color filter layer 120, and the black matrix 115 are all removed. Even if the defect occurred when the overcoat layer 125 was formed, not only the overcoat layer 125 but also the color filter layer 120 and the black matrix 115 positioned underneath should be removed.

When the rework is performed, the black matrix 115, the color filter layer 120, and the overcoat layer 125 are all made of an organic insulating material, and thus have a property of melting in KOH-based strip liquid. Therefore, the removal of these material layers is removed by dipping in KOH-based strip liquid, in which case zinc oxide (ZnO) is also dissolved in the KOH-based strip liquid. Therefore, in the case of the color filter substrate 150 for the transverse electric field type liquid crystal display device according to the first embodiment of the present invention, all components are removed by reworking using strip liquid of KOH series to obtain a transparent insulating substrate 110. do.

4A and 4B illustrate steps of removing the back electrode 113 in response to a KOH-based strip liquid when reworking a color filter substrate for a transverse electric field type liquid crystal display according to a first embodiment of the present invention. Drawing. 4a is a photograph of the back electrode surface after 1 second of dipping into a KOH-based strip liquid (13% KOH solution, 70 ° C.), and FIG. 4B is a strip of KOH-based strip liquid (13% KOH solution, 70 ° C.). It is a photograph of the back electrode surface 300 seconds after dipping.

Referring to FIG. 4A, it can be seen that the back electrode residue remains on the substrate at the start of the reaction. Referring to FIG. 4B, it is understood that no residue remains on the substrate after the reaction is completed.

On the other hand, when the back electrode is formed using a conventional indium tin oxide (ITO) as a comparative example, the indium tin oxide (ITO) is etched by a predetermined reaction to the strip solution of the KOH series, but the The etch rate is very slow and requires much more time than the complete removal of other components. Also, since it does not completely react, partial etching occurs when dipping into strip liquid of KOH series to remove the overcoat layer or color filter layer, which are defective, and thus cannot be used as a back electrode. Therefore, in the case of the color filter substrate having the indium tin oxide (ITO) back electrode, the black matrix, the color filter layer, and the overcoat layer are all removed, and an etchant containing HCl, which is a strong acid, is used in the KOH series. Indium-tin-oxide (ITO) is removed by a separate rework line.

Accordingly, the color filter substrate according to the present invention simplifies the manufacturing process even when the rework process is performed, and does not require a separate rework line for removing the back electrode, thereby reducing manufacturing costs. It can be seen that the configuration is much more advantageous in terms of.

 &Lt; Embodiment 2 >

5A through 5C are cross-sectional views illustrating manufacturing steps of a color filter substrate for a transverse electric field type liquid crystal display device according to a second exemplary embodiment of the present invention.

First, as shown in FIG. 5A, the transparent insulating substrate 210 is placed in a chamber in which a target made of indium tin oxide (ITO) or indium zinc oxide (IZO) is mounted in the sputter device. Indium-tin-oxide (ITO) or indium having a thickness of about 50 Pa to 100 Pa by depositing a transparent conductive material of Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO) by performing Macnetron sputtering A first back electrode 213a of zinc oxide (IZO) is formed.

Subsequently, as shown in FIG. 5B, the sputtering device is formed on the substrate 210 on which the first back electrode 213a formed of the indium tin oxide (ITO) or the indium zinc oxide (IZO) is formed. After the transfer to a chamber equipped with a target, characterized in that it contains zinc oxide (ZnO) as a main component and contains two or three compounds having a valence of 2 to 4 valence, and then subjected to series magnetron sputtering A second back electrode 213b having a thickness of a sufficient degree and whose main component is zinc oxide (ZnO) is formed. In this case, the sum of the thicknesses of the first back electrode 213a and the second back electrode 213b is preferably 200 kPa to 300 kPa.

On the other hand, the compound having a valence of divalent to tetravalent is Al ₂ O ₃ , Ga ₂ O ₃ , CaO, Al ₂ O ₃ is 1-3% by weight, Ga ₂ O ₃ is 0.2-2% by weight, and CaO Is characterized in that it is mixed with the zinc oxide (ZnO) in a ratio of 0.01 to 0.05% by weight, and may not be added in the case of the CaO.

Therefore, in the second embodiment of the present invention, when the second back electrode 213b includes all three compounds, zinc oxide (ZnO) 94.95 wt% to 98.79 wt%, and Al ₂ O ₃ may be 1 wt% to 3% by weight, 0.2 to 2% by weight of Ga ₂ O ₃ , and 0.01 to 0.05% by weight of CaO, and containing two compounds, 95% to 98.8% by weight of zinc oxide (ZnO), Al ₂ O ₃ It is characterized by consisting of 1 to 3% by weight, Ga ₂ O ₃ 0.2 to 2% by weight.

On the other hand, the process of forming the above-described first and second back electrode (213a, 213b) proceeds continuously in the same sputtering equipment.

FIG. 6 is a view briefly illustrating an interior of a sputtering apparatus for forming a back electrode having a double layer structure according to a second embodiment of the present invention.

As shown, the sputtering device has a "c" shape, and is divided into a first chamber 275 and a second chamber 280, and the first and second chambers 275 and 280 are different from each other. Targets 283 and 285 made of material may be mounted, or targets made of the same material may be mounted.

In this case, a target 283 made of indium tin oxide (ITO) or indium zinc oxide (IZO) is mounted in the first chamber 275 of the sputter device, and the second chamber 280 is the zinc described above. A target 285 made of a compound including oxide (ZnO) and a divalent to tetravalent element is mounted, and the substrate 210 sequentially passes through the first chamber 275 and the second chamber 280. The first and second back electrodes 213a and 213b of FIG. 5B are successively deposited.

As described above, when the back electrode 213 of FIG. 5B is formed, the sputtering device has an advantage of improving operating efficiency.

Meanwhile, referring to FIG. 5B, the first back electrode 213a is formed of indium tin oxide (ITO) or indium zinc oxide (IZO), and the second back electrode 213b is formed by the aforementioned method. Although it is shown that it consists of zinc oxide (ZnO) containing these 2 or 3 types of compounds, by changing the deposition order, a 1st back electrode is made of zinc oxide (ZnO) containing 2 or 3 types of compounds, The second back electrode may be made of indium tin oxide (ITO) or indium zinc oxide (IZO).

On the other hand, for example, when the first back electrode is formed of 150 nm thick zinc oxide (ZnO) and the second back electrode is formed of 50 nm thick indium-tin oxide (ITO), the average transmittance of light having a wavelength range of 400 nm to 700 nm Was 98.9%, and the resistivity value was found to be 260.0 × 10 ⁻⁴ μm ⁻¹ .

As another example, when the first back electrode is formed of 100 nm thick zinc oxide (ZnO) and the second back electrode is formed of 100 nm thick indium-tin-oxide (ITO), an average of light having a wavelength range of 400 nm to 700 nm is shown. The transmittance was 97.6%, and the resistivity value was found to be 15.3 × 10 ⁻⁴ μm cm ⁻¹ .

Therefore, the back electrode having a double layer structure according to the second embodiment of the present invention having a thickness of about 200 μs using only indium-tin oxide (ITO) (average transmittance of light having a wavelength range of 400 nm to 700 nm is 96.8%, Compared with the first embodiment, the specific resistance value was 3.7 × 10 ⁻⁴ μm cm ⁻¹ , and the transmittance was excellent, and the conductivity was slightly decreased. However, the role of the back electrode 213 of the color filter substrate is not a role of the actual electrode but effectively suppresses static electricity or effectively removes the generated static electricity. The conductivity required for removing static electricity has a specific resistance of 500 × 10 ⁻⁴ Ω. It requires less than cm ⁻¹ , and the back electrode of the double layer structure according to the second embodiment of the present invention does not have a problem because it satisfies this.

Next, as shown in FIG. 5C, the same process as described in the first embodiment is performed on the surface on which the back electrode 210 is not formed on the substrate 210 on which the back electrode 213 of the double layer structure is formed. By proceeding to form the black matrix 215, the color filter layer 220 and the overcoat layer 225, it is possible to complete the color filter substrate 250 for the transverse field-type liquid crystal display device according to the second embodiment of the present invention.

In the case of the color filter substrate 250 for the transverse electric field type liquid crystal display device according to the second embodiment, although a certain amount of indium tin oxide (ITO) or indium zinc oxide (IZO) is used, a predetermined compound is included. A conventional transverse electric field type liquid crystal display in which a part of the back electrode 213 is formed using zinc oxide (ZnO) to form a back electrode using only indium tin oxide (ITO) or indium zinc oxide (IZO). It can be seen that it is much more advantageous in terms of manufacturing cost compared to the color filter substrate for the device.

1 is a view schematically showing a general liquid crystal display device.

2 is a schematic cross-sectional view of a general transverse electric field type liquid crystal display device;

3A to 3F are cross-sectional views illustrating manufacturing steps of a color filter substrate for a transverse electric field type liquid crystal display device according to a first embodiment of the present invention.

4A and 4B illustrate a step of removing a back electrode in response to a KOH-based strip liquid upon rework of a color filter substrate for a transverse electric field type liquid crystal display according to a first embodiment of the present invention.

5A to 5C are cross-sectional views illustrating manufacturing steps of a color filter substrate for a transverse electric field type liquid crystal display device according to a second exemplary embodiment of the present invention.

FIG. 6 is a diagram schematically illustrating an interior of a sputtering apparatus for forming a back electrode having a double layer structure according to a second embodiment of the present invention. FIG.

<Description of the symbols for the main parts of the drawings>

110: insulating substrate 115: back electrode

Claims (10)

A back electrode having a first thickness formed on a rear surface of the insulating substrate, the back electrode having a transparent conductive material including a compound containing zinc oxide (ZnO) and a divalent to tetravalent element; A grating black matrix having a plurality of openings on an upper surface of the substrate on which the rear electrode is formed; A color filter layer formed in a plurality of openings surrounded by the black matrix; An overcoat layer formed on the front surface of the color filter layer and the black matrix Color filter substrate for a transverse electric field type liquid crystal display device comprising a. The method of claim 1, And said first thickness is in the range of 200 mW to 300 mW. A first layer having a first thickness of a transparent conductive material formed on the back surface of the insulating substrate and comprising a compound containing zinc oxide (ZnO) and a divalent to tetravalent element, and indium tin oxide (IZO) or It consists of a second layer of a second thickness of indium-zinc-oxide (IZO), and is laminated in the order of the first layer and the second layer or in the order of the second layer and the first layer. A back electrode; A black matrix having a lattice shape having a plurality of openings on an upper surface of the substrate on which the back electrode of the double layer structure is formed; A color filter layer formed in a plurality of openings surrounded by the black matrix; An overcoat layer formed on the front surface of the color filter layer and the black matrix Color filter substrate for a transverse electric field type liquid crystal display device comprising a. The method of claim 3, wherein And said first thickness is 100 mW to 250 mW, said second thickness is 50 mW to 100 mW, and the sum of said first and second thicknesses is 200 mW to 300 mW. The method according to any one of claims 1 to 4, A compound containing the divalent to tetravalent elements is Al ₂ O ₃ , Ga ₂ O ₃ , CaO characterized in that the color filter substrate for a transverse electric field liquid crystal display device. The method of claim 5, The transparent conductive material may be made of zinc oxide (ZnO) 94.95 to 98.79 wt%, Al ₂ O ₃ 1 to 3 wt%, Ga ₂ O ₃ 0.2 to 2 wt%, and CaO 0.01 to 0.05 wt%, or zinc 95% to 98.8% by weight of oxide (ZnO), 1% to 3% by weight of Al ₂ O ₃ , 0.2% to 2% by weight of Ga ₂ O ₃ Color filter substrate for a transverse field type liquid crystal display device . Depositing a transparent conductive material comprising a compound including zinc oxide (ZnO) and a divalent to tetravalent element on the back surface of the insulating substrate to form a first back electrode having a first thickness; Forming a lattice-like black matrix having a plurality of openings on an upper surface of the substrate on which the rear electrode is formed; Forming a color filter layer in the plurality of openings surrounded by the black matrix; Forming an overcoat layer over the color filter layer and the black matrix Method of manufacturing a color filter substrate for a transverse electric field type liquid crystal display device comprising a. The method of claim 7, wherein And said first thickness is in the range of 200 mW to 300 mW. The method of claim 7, wherein An indium tin oxide (IZO) or an indium zinc oxide (IZO) to cover the first back electrode before the first back electrode or after the first back electrode is formed. A method of manufacturing a color filter substrate for a transverse electric field type liquid crystal display device comprising the step of forming a second back electrode to have a second thickness. The method of claim 9, And said first thickness is 100 mW to 250 mW, said second thickness is 50 mW to 100 mW, and the sum of said first and second thicknesses is 200 mW to 300 mW.

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